In view of the foregoing background, the present invention does not have the above described disadvantages. In effect, the invention relates to a voltage ramp generator comprising a capacitance and a charging circuit that permits the generation of a charging current for the capacitance. The charging circuit for the capacitance comprises a current generator of resistance Rg2. The charging circuit for the capacitance includes means that permit the charging current for the capacitance to be proportional to (Re/Rg2)2, where Re is a resistance.
According to one particularly advantageous embodiment of the invention, the means that permit the charging current for the capacitance to be proportional to the quantity (Re/Rg2)2 comprises a degenerate current mirror. The term degenerate current mirror is used to mean a current mirror whose current ratio is not equal to the ratio of the surface areas of the MOS transistors that makes it up.
The invention also relates to a current ramp generator comprising a voltage ramp generator and a circuit that permits the conversion of the voltage ramp to a current ramp. The voltage ramp generator is a voltage ramp generator such as the one mentioned above.
According to the preferred embodiment of the invention, the components forming the voltage ramp generator and the current ramp generator are produced using CMOS technology The invention also relates to where the components are produced using a different technology, such as bipolar technology, for example.